diff --git a/build/rebuild.sh b/build/rebuild.sh
index 41a1af8..eb95b94 100755
--- a/build/rebuild.sh
+++ b/build/rebuild.sh
@@ -1,8 +1,10 @@
 #!/bin/sh
 
+set -x
+
 updates_available () {
     docker pull $1
-    if test "$(docker run -it --rm $1 /bin/sh -c 'apt -qqq update && apt -qq list --upgradable')" != ""; then
+    if test "$(docker run --rm $1 /bin/sh -c 'apt -qqq update && apt -qq list --upgradable')" != ""; then
         return 0
     else
         return 1